For many years heat treating furnaces, refractory furnaces, ceramic kilns, brick kilns, and the like, were lined with thick dense refractory brick or refractory blocks, and more recently with blankets or sheets of insulation material such as ceramic fibers made of alumina-silica, and the like, to protect the walls from extreme heat within the furnace. A common practice for anchoring the wall lining is to employ a device such as an insulation hanger in the form of an elongated stud which is welded to the furnace walls. The studs generally have teeth or notches along their sides and a retaining clip or washer having an opening therethrough in order to secure the clip to the stud after mounting or impaling insulation thereon. During the course of time, it is also necessary to replace the studs and/or remove the old insulation material and reline the furnace, as they will deteriorate during use.
Typical of such installations are the insulation hangers and installations using them shown in U.S. Pat. No. 3,738,217 to Walker; U.S. Pat. No. 4,576,532 to Hanson et al.; and U.S. Pat. No. 4,592,688 to Kramer. In all such installations it is required to individually position and weld the elongated studs over the surface of the wall to be protected, the studs extending perpendicularly from the wall surface with the open ends thereof capable of receiving the insulation material. The location and spacing arrangement of the studs is important to insure that the entire wall surface is protected and the insulation material used can be properly supported and anchored.
Heretofore, even though conventional welding techniques could be employed for anchoring the studs, it was necessary to arrange for the placement and spacing of each stud and to weld each stud separately through the use of a stud weld gun as well as checking the quality of the weld to avoid premature failure during use of the furnace. Accordingly, considerable labor and expense must be incurred in new installations or in rewelding studs when relining a furnace. In addition, the furnace must be shut down and is out of operation during the time needed to effect the insulation installation or replacement.